Apparatus for forming hollow sheet metal panels



Aug. 23, 1960 v R. F; ADAMS 2,949,875

APPARATUS FOR FORMING HOLLOW SHEET METAL PANELS Filed July 22, 1954 2Sheets-Sheet 1 FlG.l F 6 INVENTOR. RICHARD E ADAMS A TTOR NEY Aug. 23,1960 R. F. ADAMS 2,949,875

APPARATUS FOR FORMINGHOLLOW SHEET METAL PANELS Filed July 22, 1954 2Sheets-Sheet 2 124?! FIG. 5

s3 fi e4 56 $44 FIG 6 42 66 58 I8 I INVENTORZ 42 RICHARD F. ADAMS 7 8| yATTORNEY APPARATUS FOR FGG HOLLOW SHEET METAL FANELS Richard F. Adams,Alton, 111., assignor to Olin Mathisson Chemical Corporation, acorporation of Virginia Filed July 22, 1954, Ser. No. 445,108

20 Claims. (Cl. 113-44) This invention relates to a pressure fitting orconnection and more specifically to a fluid pressure injection devicefor inflation of hollow articles.

In the fabrication of hollow articles from sheeting by a method such asthe pressure welding method, it is necessary to communicate fluidpressure to the interior surfaces of the embryonic fluid passageways inorder to develop the passa eways in accordance with. a desired layout aspredetermined by the presence of a thin layer of separation material,also referred to as stop weld, between these surfaces. It is frequentlydesirable that such connection or fitting be adaptable for associationwith the sheet metal units only during the initial manufacturingoperations including inflation and be removable before furtherfabrication.

In the prior art methods of forcing hollow metal articles to shape byfluid pressure, various fittings have been employed. According to onescheme, threaded fittings are formed or attached in some manner to thestructure to be inflated (US. Patent Nos. 1,709,864, Muflly; 1,712,-085, Litle; and 2,493,135, Gruetjen). The obvious disadvantage of theseis that the addition of such fittings involves a hole punching or abreech forming process, brazing or welding operation together with athreading operation, all of which are costly and time consumingoperations. Other devices used for the purpose are rather complex andrequire the formation of a flange on the article (US. 1,925,854,Squires; 2,047,296, Squires; and 2,221,539, Gehret) which is ratherimpractical with sheet material of relatively thin gage and obviouslyuneconomical for mass production of sheet metal items for the consumermarket. A further illustration of these prior complex devices is U.S.2,350,541 (Stulen) which, while suitable for large costly items such asan aeroplane propeller blade, would upon reduction to a scale for thepurposes of this invention become an assembly of costly small precisionparts not adaptable to the sheet metal operation to which this inventionrelates and diflicult to keep in operating condition. Furthermore, noneor" the foregoing prior devices is capable of either prying open theedge of the sheet at the linearily exposed stop weld or is capable ofbeing connected and further enlarging the opening by insertion and henceeach is suitable for use only with a forged or machined end fitting.

Merely applying a pointed tool to the parting line of stop weldappearing at the edge of a sheet to make a tubular entrance and thenforcing into the opening a piece of tubing for applying pressure to thesheet and it afterward to remain as an inlet or outlet for a heatexchange unit or the like is not satisfactory. Such a schemenecessitates that the sheet be extremely thick walled so that pressingthe tube in will not tear the sheet and still enable the fitting towithstand pressure of up to 10,000 pounds per square inch or higher.This places a limitation on the thinness of gage with which theaforementioned pressure welding method may be practiced. Anotherdisadvantage is that the presence of permanent fittings of this typeinterferes with the stacking, handling,

from the edge of a hollow sheet metal article in sealing relationshipwith the fluid pressure inlet at such edge. Still another object is toprovide a new and improved apparatus adapted for quickly forming ahermetically sealed connection to the undeveloped interior of a pres--sure welded sheet metal blank and, if desired, for provid-- ing aconnection to the developed cavity of such a sheet metal unit forfurther fabricating operations.

embodiments of the invention.

In accordance with this invention, in general terms, a: fluid pressureadmitting member is provided and is in-- serted between the sheetmaterial portions or labia sur-- rounding the inlet lamination exposedat the edge of a sheet unit and the labia are compressed about the fluidpressure admitting member and against each other immediately adjacentsaid member by a clamping memher. The pressure admitting member, formedprefer-- ably of stainless steel, consists of an inflation needle orcannula at one end and a high pressure coupling at the other end forconnection to a source of fluid. Intermediate the needle and thecoupling this member is provided preferably with an exterior flangewhich may be provided with flats or a knurl or the like to permitgrasping and in some instances even turning the member which facilitatesits removal after the pressure admitting member has served its purpose.The inflation needle is a tubular member which may be either circular,oval, or lenticular in cross section, and the forward end of it is atleast rounded to facilitate insertion between the partially separatedlabia of the edge opening. The forward end of the needle in itspreferred form may be provided with either a chisel-shaped point or aconical point to enable its being inserted to bring about initialseparation of the labia. The external member takes the form of aclamping device capable of swaging the labia tightly about the needleand for closing up any gap which may occur at the corners of the labiaand which would permit a leak between the exterior of the needle and theinterior of the labia. The parts of the clamping member may be borneeither by the press platens between which the hollow sheet unit isinflated or by an implement or tool also carrying the fluid pressureadmitting member.

The general nature and extent of the invention will be better understoodfrom a description of the several specific embodiments illustrated inthe accompanying drawing in which:

Figure 1 is a side elevational view partially in cross section showingpart of a heat exchange unit undergoing inflation in accordance with anembodiment of this invention;

Figure 2 is an elevational partial view taken on line lIII of Figure 1;

Figure 3 is a perspective fragmentary view showing a fitting associatedin accordance with this invention with a pressure welded sheet metalunit such as a refrigerator evaporator prior to inflation;

Figure 4 is a cross sectional view showing a modification of the needledevice of Figures 1 and 2;

Figure 5 is an elevational partial view of a device in accordance withanother embodiment of the invention;

Figure 6 is a side cross sectional view taken on line Patented Aug; 23,1960" Another object is to' Other objects and advantages will beapparent from the description and accompanying drawing relating tovarious preferred 3 VIVI of the device of Figure into which a sheetmetal unit has been inserted in accordance with this invention;

Figure 7 is a cross sectional view taken on line VlIVII of Figure 6 thebetter to illustrate the structural details; and

Figure 8 is a perspective view of the front end of the needle shown inFigures 5, 6 and 7.

In Figures 1 and 2, a pressure welded sheet 1 is shown inflated betweenpress platens 2 and 3 with a fluid pressure communication device inaccordance with one embodiment of this invention. The pressure admittingmember consists of circular tubular needle 4 with a rounded end 211 anda bore which is in communication with the bore of a coupling 5 such as aHanson fitting or the like, suitable for connection with a source ofhigh pressure fluid. The enlarged midsection between the needle 4 andcoupling 5 is preferably provided with an exterior flange 6 which isserviceable not only as a grasping and turning means but also as apositioning means. The exterior clamping member is a two part clampconsisting of an upper jaw 7 supported on upper platen 2 with the aid offastening means such as bolts 8 and a lower jaw 9 supported on lowerplaten 3 with the aid of any suitable fastening means such as bolts 10.The lower jaw 9 is preferably provided with an arcuate seat 24 having anarcuate groove 25 for reception of the flange 6. Desired positioning ofjaw 7 and 9 is accomplished with the aid of shims 26 and 27,respectively. As shown in Figure 2, the upper jaw 7 is provided with:spaced pressure pads 11 and 12 intermediate which is the arcuate diesurface 13 adapted to compress upper labium 14 of sheet 1 against needle4 with slight plastic deformation. Similarly lower jaw 9 is providedwith pressure pads 15 and 16 intermediate which is disposed arcuate diesurface 17 adapted to compress lower labium 18 of sheet 1 with slightplastic deformation tightly against needle 4. Pressure pads 11, 12, 15and 16 of generally rectangular shape and flat surfaced usually areadapted to compressively and plastically deform or swage the metal ofthe sheet 1 immediately adjacent the inserted needle 4 at the corners 19and 20 of the labia 14 and 18 so as to accomplish a form fitting sealabout the needle.

In operation, the inlet lamination 22 which presents itself as a line atedge 34 of the flat rolled sheet metal unit 1 is first located, as shownin one part of Figure 3, and the labia 14 and 18 are initially priedapart in any manner with any suitable instrumentality after which therounded end 21 of needle 4 is presented to and inserted into the openingat lamination 22 until the edge of sheet 1 is abutted against theenlarged midsection of the pressure admitting member which acts as astop 23. The entire unit 1 is next placed between the opened platens 2and 3 of a press where the pressure admitting member, connected to afluid pressure supply line 31 as shown in Figure 3, is positionedproperly between the jaws 7 and 9 of the exterior clamping member byseating flange 6 in arcuate groove 25 in the lower jaw 9. The platens 2and 3 of the press are then brought together to the desired closedspacing at which position jaws 7 and 9 have been articulated to theirposition of closest approach. In this position arcuate die surfaces 13and 17 of jaws 7 and 9 respectively compress the labia 14 and 18, whichdelineate lamination 22 of sheet 1, about the major circumferentialportion of the exterior side wall of needle 4. In this position of thejaws, pressure pads 11 and 15 are brought into such close spacing as todeform the sheet 1 sufiiciently to reduce the thickness of the metalnoticeably at 28 immediately adjacent the needle 4 so as to close up theopening at corner 19 of the labia and to compress the metal at thiscorner firmly against needle 4. Similarly pressure pads 12 and 16 act onthe metal at 29 to accomplish closure and compression at corner 20 ofthe labia 14 and 18. The deformation, evidenced by a bead 30 of deformedmetal alongthe outer periphery of 4 compressed areas 28 and 29, providesa hermetic seal. While thus secured between needle 4 and the diesurfaces of jaws 7 and 9, the separated labia form a fluid pressureconnection enabling inflation between platens 2 and 3 to erect fluidpassageways such as 32 and 33 in the sheet metal unit 1.

In the form of inflation needle shown in Figure 4 the shape in crosssection is lenticular and tapers down mostly laterally to a somewhatsmaller cross section at the point which is preferably necked down androunded but conical pointed, knife blade shaped, or chisel-shaped, i.e.has a point or linear edge, to facilitate entry between and even initialparting of the labia 14 and 18 at lamination 22 at edge 34. Convex upperface 35 of the needle operates on labium 14, for example, while lowerface 36 operates on labium 18. Lateral edges 37 and 38 are adapted tothe form of lamination 22 when opened at the corners 19 and 20. Thisform of needle may be advantageously provided with a dual boreconsisting of passages 39 and 40 extending up toward the chisel point atthe forward end but terminating short of the point in lateral outlets,preferably rearwardly extending and opening at the lateral edges 37 and38 respectively at points forwardly of where the jaws 7 and 9 press uponthe needle. The design of needle and its bend-back fluid passagesminimizes the chances of scraping metal into the passages 39 and 40 tocause a closure. While the openings of these passages may be alsodisposed on surfaces 35 and 36, it is preferred that they be at edges 37and 38 inasmuch as these are more tapered and are least pressed by themetal of sheet 1 at the lamination 22.

In the embodiment of Figures 5, 6 and 7, the pressure admitting memberand the external compression member are constructed as parts of a singleimplement or mechanism, which includes a needle or cannula 41, anexternal compression applicator 42, a transmitter member or transmissionsleeve 43, a compression operator 44 and a carrier and impact block 45to one end of which the needle 41 is connected and near the other end ofwhich there is attached any suitable high pressure coupling 46.

The carrier block 45, which is a piece of steel of generally cylindricalshape, is provided with a fluid passageway or bore 47 communicating withboth the needle 41 and the coupling 46. Mounted on the carrier block 45is the compression applicator 42 and the transmitter 43 the latter twoof which are screw threadedly engaged at external threads 48 onapplicator 42 and internal threads 49 on the transmitter 43. Fixedangularly about the carrier block by any suitable fastening means suchas set screw 50 is a guide and support ring 51 from which there extendshandle 52 which may take the form of a pistol grip by which the entiremechanism of this embodiment may be supported or grasped manually 51dmanipulated as desired. The rear end or shank 53 of block 45 is adaptedto be struck by a mallet, for example, or by an air hammer yieldablycarried on lugs 54 and 55 integral with the carrier block 45 to driveneedle 41 between the labia 14 and 18 of sheet metal unit 1 as shown inFigure 6. Also mounted on carrier block 45 are thin, forwardly extendingpins 56 and 57 which slidably engage with holes 58 and 59 in theapplicator and prevent rotational movement of the applicator 42 assleeve 43 and its threads 48 are turned. The carrier annular protrusion60 forms an abutment for the internal flange 61 of the sleeve 43 andtakes the reaction force as the sleeve is turned down on applicator 42.

Needle 41 consists of circular shank 62 at the posterior with a suitableeasily engageable and disengageable mechanical coupling such as spline63 at one end and with a flange 64 near the other serving as a stop forthe edge of the sheet metal unit 1, as shown in Figure 6. Ahead of theshank 62, the needle 41 has a tapering conical portion 65 designed forcoaction with jaws 66 and 67 of compression applicator 42. At the frontend, the needle terminates in a conoidal'pointed shape 68' with a chiseledge 69 at which there is an opening 78 set back from and bisecting theedge 69. Opening 70 is in communication with the bore 71 of the needle.Between the point shape 68 and the conical portion 65 is a circulartubular extension 72 of the needle the purpose of which is to positionthe point 68 and its opening SllffiClGllilY ahead of the jaws 66 and 67so as to make the point readily visible and easy to apply to the edge ofsheet unit 1 to spread apart the labia 14 and 18 while the jaws 66 and67 are in the forward open position and so as to place the opening 70ahead of the jaws 66 and 67 during the compression operation which wouldotherwise seal the opening.

Mounted slidably on the forward cylindrical portion 73 and pins 56 and57 of the carrier block is the compression applicator 42 which takes theform of a cuplike or hollow cylinder the front of which at jaws 66 and67 is solid except for the slot 74 intermediate the jaws and whichterminates at 75 short of the open rear end of the cylindrical body ofthe applicator 42 which is thus nearly bisected by the slot. Theapplicator is provided with external threads 48 engageable with theinternal threads 49 of the sleeve 43. Where desired, threads 48 and 49may be tapered pitch threads to accentuate the clamping actionobtainable. The hollow cylindrical body of the applicator 42 is soformed as to be somewhat sprung open at the front end of the slot 74 sothat compression applicator jaws 66 and 67 are spaced apart yieldably agreater distance when the threads 48 and 49 are in but minor or noengagement. As the threads are screwed into greater engagement thedistance between the jaws 66 and 67 at slot 74 is reduced. Upper jaw 66is provided at the slot 74 with pressure pads 76 and 77 and the lowerjaw 67 is provided at the slot 74 with pressure pads 78 and 79. Betweenpads 76 and 77, the upper jaw 66 is provided with an arcuate die surface80 which is part of a cone larger than the conical portion 65 of theneedle 41 by an amount slightly less than the thickness of the labium14. Between pads 78 and 79, the lower jaw 67 is provided with an arcuatedie surface 81 which is part of the same cone as the die surface 80 ofthe upperjaw 66.

Sleeve 43 is rotatably mounted on carrier block 45 and engages at itsinternal threads 49 with the threads 48 of the applicator 42 so as toimpart longitudinal movement to the applicator as sleeve 43 is turned bythe compression operator 44 which takes the form of a rotatable ringfrom which there extends a handle 82. The compression operator ring 44is mounted rotatably on the sleeve 43 and engages by means of theflip-flop pawl 83 with it at the ratchet teeth 84 carried externallyabout the sleeve 43. Operator ring 44 is rotatably confined on sleeve 43by support ring 51 which together with protrusion 60 constrains sleeve43 at flange 61 longitudinally while permitting rotational movement ofboth sleeve 43 and operator ring 44.

The form of the needle point 68, more clearly illustrated in Figure 8,is advantageous in that the opening 70 is set back from the bisectededge 69 and hence will not tend to pick up particles of metal or tobecome shut as edge 69 pries open the labia 14 and 18 of sheet 1.

In operation, the device of this embodiment while grasped or supportedat grip 52 is manipulated so as to present edge 69 of the separableneedle 41 to the edge of sheet unit 1 in proper position for prying openthe labia 14 and 18. When so positioned, hammer blows are struck uponshank 53 of the carrier block 45 either manually or by means of an airhammer attached at lugs 54 and 55 to drive needle 41 between the labiauntil the edge portion of sheet unit 1 has passed into slot 74 betweenjaws 66 and 67 sufliciently to seat the labia 14 and 18 against flange64 on the needle 41. Next, with the pawl 83 properly set for screw-downoperation, the handle 82 is oscillated manually or otherwise to put pawl83 carried on compression operator ring 44 into 6 V one-way positiveengagement with the ratchet teeth 84 on transmission sleeve 43, therebyturning the sleeve 43 to screw-down the compression applicator 42. Thisoperation, which brings the jaws 66 and 67 closer together and alsotoward the conical portion 65 of the needle 41, results in seizure andswaging of labia 14 and 18 between the needle 41 and the jaws 66 and 67which is shown in Figure 7.

When the jaws are positioned as shown in Figure 7, at which positionpressure pads 76 and 77 and arcuate die 88 of jaw 66 deform the metal ofsheet unit '1 between them and pressure pads 78 and 79 and arcuate die81 of jaw 67, fluid pressure is released to enter at coupling 46 and tobe admitted into the interior of sheet metal unit 1 via the bores 47 and71 of the block 45 and needle 41, respectively.

Upon completion of the inflation operation, after the fluid pressure isshut off, the jaws 66 and 67 are opened by throwing the flip-flop pawl83 to engage with teeth 84 to accomplish unscrewing of applicator body42 and sleeve 43 as handle 82 is again oscillated. Release of thecoupling 63 permits the needle 41 to remain in sheet unit 1, if desired.Otherwise coupling 63 may be dispensed with and the entire devicetogether with needle 41 is removable from the inflated sheet metal unit1.

While the compression operator has been described as including themechanical elements of a pawl, a ratchet and a screw threadedtransmission sleeve it is to be understood that this preferredembodiment is only illustrative of the inventive principle involved andthat the compression clamp operating means may be a pneumatic orhydraulic cylinder actuated possibly by the inflation medium. It isevident to those skilled in the art that this embodiment is amendable toinclusion of a fluid pressure valve operated by a trigger located in thepistol grip 52 which would initiate not only a fluid pressure actuatedclamping pressure applicator but also feed fluid pressure for inflationto the needle 41.

By means of this invention there is obtained not only a hermetic sealduring the step of fluid pressure inflation of a sheet metal unit havingan internal pattern of lamina but also the provision of a connectionthat may be retained with the sheet after inflation to aid in othermanufacturing operations such as the washing and the drying of theinterior walls of the passageways, after which the connection is readilyremovable.

It will also be evident to those skilled in the art that this inventionhas utility in connection with inflation of articles made from sheetmaterial by methods other than pressure welding wherein an interposedstop weld material is employed.

Since many other embodiments of this invention may occur to thoseskilled in the art, it is to be understood the foregoing is intended byway of illustration of a preferred embodiment and not as a limitation ofthe scope of the present invention except as set forth in the appendedclaims.

What I claim is:

1. A device for communicating fluid pressure to the interior of a sheetmetal unit partially laminated in accordance with a predetermined finalpassageway design including an inlet, comprising interior meansdetachably securable to said unit in fixed relationship with respectthereto, said means consisting of needle and driving portions, saiddriving portion being adapted for inserting said needle portion into theunit at said inlet in said fixed position for holding apart the sheetmetal portions with desired configuration and for admitting a fluidunder pressure into said sheet metal unit at said inlet, and pair ofspaced diametrically opposed exterior means axially and transverselyaligned with each other and maintained in alignment with said interiormeans for pressing only adjacent sheet metal firmly about said needleportion while leaving the rest of the sheet metal unit substantiallyfree from said clamping pressure to secure said means to said unit andprevent leakage of said fluid.

2. A device for communicating fluid pressure to the interior of a sheetmetal unit partially laminated in accordance with a desired passagewaydesign including an exposed inlet lamination defined by opposed sheetmetal labia comprising a tubular needle for holding apart the sheetmetal labia on opposite side of said inlet lam-ination and for admittinga fluid under pressure into the lamina of said sheet metal unit, a pairof spaced clamping jaws operatively connected to said needle, said jawbeing provided with a recess in alignment with said needle and adaptedfor coaction therewith to conform said labia about said needle bypressing and plastically forming said separated labia and the metalimmediately adjacent thereto against said needle inserted between saidlabia while leaving the rest of the unit of the said unit substantiallyundistorted, and means for actuating said jaws operatively connectedthereto for opening and closing said jaws, said needle having a portionthereon adapted for receiving a driving force for driving said needleinto said inlet lamination.

3. A device for communicating fluid pressure to the interior of a sheetmetal unit partially laminated in accordance with a desired passagewaydesign including an exposed inlet lamination defined by opposed sheetmetal labia comprising a tubular needle of circular cross-section forholding apart the sheet metal labia on opposite sides of said inletlamination and for admitting a fluid under pressure into the lamina ofsaid unit, said needle having a point of a shape adapted for enablingthe needle to be readily inserted into said lamination and having aportion thereon adapted for receiving a driving force for driving saidneedle into said inlet lamination, a pair of spaced diametricallyopposed clamping jaws operatively connected to said needle, said jawsbeing provided with a recess in alignment with said needle and adaptedfor coaction therewith to conform said labia about said needle bypressing and plastically deforming said separated sheet metal labia andthe metal immediately adjacent thereto against said needle insertedbetween said labia while leaving the rest of the sheet metal unitsubstantially undistorted, and means for actuating said jaws operativelyconnected thereto for opening and closing said jaws.

4. A device for communicating fluid pressure to the interior of a sheetmetal unit partially laminated in accordance with a desired passagewaydesign including an exposed inlet lamination defined by opposed sheetmetal labia comprising, a tubular needle of circular cross-section witha rounded point for holding apart the sheet metal labia on oppositesides of said inlet lamination and for admitting a fluid under pressureinto the lamina of said unit, a pair of spaced diametrically opposedjaws spaced from and operatively connected to said needle, said jawsbeing provided with a recess in alignment with said needle and adaptedfor coaction therewith to conform said labia about said needle bypressing and plastically deforming said separated sheet metal labia andthe metal immediately adjacent thereto against said needle insertedbetween said labia while leaving the rest of the unit substantiallyundistorted, each of said jaws having recessed arcuate die surfacesmaintained in alignment with each other and said needle for coactiontherewith and having on opposite lateral sides of each recess a pressurepad for coaction with corresponding pads of the other for swaging themetal of said unit immediately adjacent of said needle with maximumseverity, and means for actuating said jaws operatively connectedthereto for opening and closing said jaws.

5. A device for communicating fluid pressure to the interior of a sheetmetal unit partially laminated inaccordance with a desired passagewaydesign including an exposed inlet lamination defined by opposed sheetmetal labia comprising, a tubular needle of circular cross-sec- 8 tionwith a rounded point for holding apart the said labia on opposite sidesof said inlet lamination and for admitting a fluid under pressure intothe lamina. of said unit, a pair of diametrically opposed jaws spacedfrom and operatively connected to said needle, said jaws being providedwith an arcuate recess in the alignment with said needle and adapted forcoaction therewith to conform said labia about said needle by pressingand plastically deforming said separated labia and the metalinrmediately adjacent thereto against said needle inserted between saidlabia while leaving the rest of said sheet metal unit substantiallyundistorted, said jaws having an arcuate recessed die surface inalignment with said needle for coaction therewith and having on oppositesides of said arcuate recess extended pressure pads for swaging themetal of said unit adjacent of said labia, and means for actuating saidjaws operatively connected thereto for operating and closing said jaws.

6. The device of claim 2 wherein the needle is of oval cross-section.

7. A device for communicating fluid pressure to the interior of a sheetmetal unit partially laminated in accordance with a desired passagewaydesign including an exposed inlet lamination defined by opposed sheetmetal labia comprising, a tubular needle of lenticular crosssection forholding apart the sheet metal labia on opposite sides of said inletlamination for admitting a fluid under pressure into the lamina of saidsheet metal unit, clamping jaws, means for operatively connecting saidjaws to said needle, said jaws being provided with a recess in alignmentwith said needle and adapted for coaction therewith to conform saidlabia about said needle by pressing and plastically deforming saidseparated sheet metal labia and the metal immediately adjacent theretoagainst said needle inserted Within said inlet lamination while leavingthe rest of the sheet metal unit substantially undistorted, said needlehaving lateral edges tapering so as to bring the apices of thelenticular crosssection closer together at the front end of said needlewhich is formed to a chisel edge and also having dual fluid pressurepassageways opening laterally adjacent the chisel edge, and actuatingmeans for said jaws operatively connected thereto for opening andclosing said jaws.

8. The device of claim 3 wherein at least a portion of the needle ofcircular cross-section tapers intermediate the point and rear endportion to a lesser cross-section toward the point.

9. A device for communicating fluid pressure to the interior of a sheetmetal unit partially laminated in accordance with a desired passagewaydesign including an exposed inlet lamination defined by opposed sheetmetal labia comprising, a tubular needle of circular cross-section forholding apart the sheet metal labia on opposite sides of said inletlamination and for admitting a fluid under pressure into the lamina ofsaid sheet metal unit, said needle terminating at the front in aconoidal portion the anterior of which is in the form of a chisel edgebisected by the open end of the coaxial fluid pressure passageway in theneedle, said opening being set back from the chisel edge, diametricallyopposed clamping jaws operatively connected to said needle, said jawsbeing provided with a recess in alignment with said needle and adaptedfor coaction therewith to conform said labia about said needle bypressing and plastically deforming said separated sheet metal labia andthe metal immediately adjacent thereto against said needle insertedwithin said inlet lamination while leaving the rest of the sheet metalunit substantially undeformed, and means for actuating said jawsoperatively connected thereto for opening and closing said jaws.

10. The device of claim 1 wherein the needle portion is of lenticulartransverse cross section.

11. A device for communicating fluid pressure to the interior of a sheetmetal unit partially laminated in accordance with a desired passagewaydesign including an inlet lamination extending to an edge of said sheetmetal unit and defined by opposed sheet metal labia comprising asupport; a carrier block mounted on said support and having a fluidpassageway therethrough; a cannula mounted on the front end of saidblock and coupled with said fluid passageway for holding apart saidlabia on opposite sides of said inlet lamination and for admittinginflation fluid under pressure into the lamina of said sheet metal unit,said cannula having a point constructed to permit the cannula to bereadily inserted adjacent the mid-section of said inlet laminationbetween the corners of said labia for separating the labia and includinga fluid discharge opening surrounded by said point, and exterior clampmeans mounted on said carrier block and including spaced diametricallyopposed members movable toward and away from said cannula and adaptedfor receiving between them the edge portion of said sheet metal unit atsaid inlet lamination and said cannula for applying oppositely directedcompression forces externally of said labia toward said cannula wherebysaid sheet metal about said inlet lamination is plastically deformed toconform said labia snugly' about said cannula.

12. The device of preceding claim 11 wherein the cannula isdisengageably mounted on the front end of said block and disengageablycoupled with said fluid passageway.

13. The device of preceding claim 11 wherein the cannula has an enlargedrear end portion extending outwardly beyond the front portion of thecannula, said rear end portion being adapted for seating on the frontend of the block to center the cannula with respect to saiddiametrically opposed members of the clamp means and having a shoulderfor positioning the cannula with respect to said edge of the sheet, saidrear end portion being adapted to be mounted disengageably on saidcarrier block and disengageably coupled with said fluid passageway.

14. A device in accordance with preceding claim 11 wherein said carrierblock includes means for accepting a forwardly directed impact blow forthe purpose of driving said cannula between said labia.

15. A device in accordance with preceding claim 11 wherein the clampmeans is fluid pressure operated.

16. A device in accordance with preceding claim 11 wherein impact isprovided by a fluid pressure operated means.

17. The device of preceding claim 11 wherein the clamp means is fluidpressure operated and wherein the impact is provided by a fluid pressureoperated means.

18. The device of claim 11 wherein the cannula includes a conicalportion tapered down toward the point and said clamp means consists ofan externally threaded compression member the front end of which isdiametrically slotted and carries conical die members coaxially arrangedabout the cannula for coaction with the conical portion of the cannula,said member being slidably mounted on the carrier and constrainedagainst rotation and an internally threaded rotatable sleeve screwthreadedly engaging said compression member for converting therotational motion of said sleeve to longitudinal translation of saidcompression member and its die members with respect to said conicalportion of the cannula Whereby the spacing between said conical portionsof the cannula and the die members may be varied to clamp andplastically deform and to subsequently release the sheet metal in theregion of said labia, and means for imparting rotational motion to saidsleeve member in one di- 7 rection to form a hermetically sealedconnection of said cannula with said inlet lamination and for impartingrotational motion to said sleeve member in the opposite direction todisengage said clamp means from said sheet metal.

19. A device for communicating fluid pressure to the interior of a sheetunit partially laminated in accordance with a desired passageway designincluding an exposed inlet lamination defined by opposed sheet labia,compris ing hollow interior means for holding apart the said sheet labiaon opposite sides of said inlet lamination and for admitting fluid underpressure into the lamina of said sheet unit, and exterior meansoperatively connected to said interior means, said exterior means beingbifucated for reception of a portion of said unit containing said inletlamination and having adjustable opposed moveable members, complementaryrecesses in each of said members intermediate the ends thereof forcoaction with the interior means for passing and plastically deformingsaid separated sheet labia and portions of said sheet unit mediatelyadjacent thereto between said members to conform said labia firmlyagainst said interior means to prevent leakage of said fluid betweensaid interior means and said labia while leaving the rest of the sheetunit substantially undistorted, and actuating means for said membersoperatively connected to said exterior means for opening and closingsaid members.

20. A device for communicating fluid pressure to the interior of a sheetmetal unit partially laminated in accordance with a desired passagewaydesigned including an exposed inlet lamination defined by opposed sheetmetal labia comprising a tubular needle having a point of a shapeadapted for enabling the needle to be readily inserted into said inletlamination for holding apart said sheet metal labia on opposite sidesthereof and for admitting a fluid under pressure into the lamina of saidsheet metal unit, spaced diametrically opposed clamping jaws, said jawsbeing provided with a recess in alignment with said needle and adaptedfor coaction therewith to conform said labia about said needle bypressing said separated sheet metal labia and the metal immediatelyadjacent thereto against said needle inserted within said inletlamination with suflicient pressure to deform the metal at least at thecorners of said labia and hermetically seal said unit with respect tosaid needle leaving the rest of the sheet metal unit substantiallyundistorted, a first alignment means on at least one of said jaws, asecond alignment means on said needle for engagement which said firstalignment means in cooperating relationship with each other for aligningthe front part of said needle at said clamping jaws, and actuating meansfor said jaws operatively connected thereto for opening and closing saidjaws.

References Cited in the file of this patent UNITED STATES PATENTS464,736 Stapley Dec. 8, 1891 765,827 Felker July 26, 1904 1,052,193 VogtFeb. 4, 1913 1,522,051 Fulton Ian. 6, 1925 2,350,541 Stulen June 6, 19442,662,273 Long -2 Dec. 15, 1953 2,756,487 Heidorn July 31, 19562,779,086 Rieppel et al. Jan. 29, 1957 2,882,588 Rieppel Apr. 21, 1959FOREIGN PATENTS 523,948 Great Britain July 25, 1940 106,492 Sweden Apr.20, 1943 695,640 Great Britain Aug. 12, 1953 UNITED STATES PATENT OFFICECERTIFICATE OF CORRECTION Patent N00 2,949,875 August 23 1960 Richard F.Adams Column 1, line 34, for the patent number "1,70%8641 read 1 709 865column 10, line 18, for passing read messing Signed and sealed this 25thday of April 1961.,

(SEAL) H6812 h ERNEST W SWIDER LADD Attesting Oflicer I Commis sioner ofPatents

